Machines and implements play an important role in agriculture. Thirty years after its introduction in the Brazilian national territory, the no-tillage system was consolidated as a conservation technology widely accepted among farmers, with systems adapted to different regions and different technological levels, from large to small farmers using animal traction.
The seeder-fertilizer or no-tillage planters are machines that perform the implementation of annual crops by sowing on land wherein no periodical preparation of the soil was performed and with the presence of vegetal coverage. There is a minimum reguired mobilization of soil, only on sowing rows. Thus, it is possible to sowing after the harvest of the previous crop. Usually the units of seeders are combined to fertilizing units, hence the name seeder-fertilizer.
The no-tillage, defined as the process of sowing in soil not revolved, in which the seed is placed in grooves or pits, with enough width and depth for the proper coverage and contact of the seeds with the earth, is today understood as a system with the following grounds, that interact:
Elimination/reduction of tillage operations. As a result, it avoids the surface sealing, due to the impact of raindrops; consequently, reduces the surface seepage and increases infiltration, drastically reducing erosion. There is more maintenance of the aggregate stability, improving the soil structure by preventing subsurface compaction. It reduces losses of water by evaporation, increasing the availability of water for plants, the biological activity of the soil and the maintenance of organic matter of the soil.
Use of herbicides for weed control. The use of desiccant herbicides means replacing the mechanical energy of soil preparation for the chemical energy (herbicide). It is essential the use of integrated weed control methods, such as the use of coverage crops, crop rotation and specific herbicides.
Formation and maintenance of mulch. It provides protection against the impact of rain drops, reducing surface runoff, sediment transport and hence erosion. It also acts on the soil protection against the effect of sunlight, reducing evaporation, the soil temperature and the thermal amplitude of the soil, and against the action of winds. With its decomposition, it incorporates organic matter to the soil, required for a larger and richer microbial activity, which allows greater nutrient recycling. In addition, it aids in weed control, by suppressing or allelopathic effect.
A precision seeder consists of chassis or tool holder bar, engaging and coupling to the tractor system, transportation system, containers for seed and fertilizer, and driving and transmission system, systems for dosage and distribution of seeds and fertilizer, sowing units, line markers and stirrups. The sowing units are formed by vegetation cutting unit, groove openers for fertilizer, groove openers for seed, depth control system of grooves for seeds, groove grounding system and compacting system of soil over seeds.
The disks cut straw and open a groove on which other components work. The most commonly used are straight, with diameters between 18″ and 20″.
The larger is the diameter, the greater will be the force necessary for them to penetrate the soil, because of their larger contact area. However, they have the advantage of passing on vegetation and have lower bushing problems.
The cutting blades are designed and should be regulated only for cutting straw, not exceeding a depth of more than 6 cm. Preferably, they should be provided with lateral movements, besides vertical adjustments. The deeper, the greater the unwanted mobilization of the soil. Moreover, the excess pressure causes the disk to only push the straw to the bottom of the groove, does not cutting the plant material adequately and causing the “basketing” of the seeds. The use of cutting disks in “zig zag” also helps preventing bushings; the greater the mismatch of the lines, the greater is the flow of straw between the grooves.
Document US 2012/0141199 A1 document, filed on Dec. 2, 2010, by Coupling Corporation of America, and entitled “Shaft Connection Assembly”, describes a set for threaded connection of shafts in order to transfer torque between two shafts, including a hub and a rim. The hub includes a flange part and a sleeve part, the sleeve part having a plurality of sleeve segments formed by longitudinal cuts along the length of the sleeve part so that when the rim is linearly forced, axially outwardly of the flange part, the sleeve segments exert a clamping force on each of the two axes disposed within a passage formed by the hub. The clamping force prevents the relative movement of the first shaft relative to the second when the shafts are rotated around a common axis. This document presents a union scheme by means of a thread that could be adjustable, but there is no information about the existence of rollers inside, not even one can check its applicability for cutting disks of planters and subsoilers.
Document BR 8402706-1, filed on Mar. 2, 1993, by Marchesan Implements and Agricultural Machinery Tatú SA, and entitled “Cutting disk used in small and medium-size machines for no-tillage”, describes a cutting disk used in small and medium-size machines for no-tillage comprising an integral support (01) defined by superior double vertical segment (02), intermediate pivoting (03), double inferior re-curved segment (04) for receiving the cutting disk (05) intermediate fastener element (06) provided with horizontal (06-A) and vertical (06-B) bushings, assembly articulation axes (07) and (08) to the front coupling (09) and rear coupling (10) for fastening the cutting disk (01) to the chassis (11) of the agricultural planter machine. A workload set of the disks for cutting and monitoring the irregularities of the ground is defined by the arrangement and constructive form of anchoring of traction spring (12) in a horizontal plane and provided with adapters (13) provided with helical conformation for insertion along with the ends wires of the traction spring (12) with screw (16) of threaded length to adjust the tension load of the traction spring (12) according to the field conditions.
Document EP 0555745, filed on Mar. 25, 2004, by Amanozen-Werke H. Dreyer GmbH & Co. Kg, and entitled “Drill Machine”, describes a sower having a structure in which the disks (1) of the coulters of seeds are arranged by means of a retention arm (3), the disks (1), respectively, being rotatably mounted on the retention arms (3) via a rotary roller having an shaft, an extractor (6, 16) being arranged by means of a support (4, 15) on each side of the disk (1), the support (4) of the first separator (6), arranged on the side of the disk (1) in which the retention arm (3) is situated, being fastened to the mounting (14) of the rotary roller and/or retention arm.
The international patent application WO 2012/055611, filed on Aug. 30, 2011 by Robert Bosch GmbH, and entitled “Arrangement for transmitting torque between the shaft and the hub,” describes a set (100) for transmitting torque between a shaft (48) and a hub (102), wherein the hub (102) has at least approximately the inner geometry of an eguilateral polygon with n sides (122), whose lateral surfaces are supported against an engagement part (104), which is of circular cross-section, the shaft (48), and wherein the shaft has at least one conductor part (108) which is rotatably connected with respect to the engagement part assembly (104) and extending toward a niche (124) of the polygon of n sides (122).
U.S. Pat. No. 4,494,889, filed on Jul. 14, 1983 by Reliance Electric Company, and entitled: “Shaft bushing and hub assembly” discloses a set of bearing and hub for the mounting of pulleys, sprockets, gears, joints and similar machines elements on a shaft, in which two types of conical bearing are used, the bearings having bodies with a single identical inclination used as a single hub, which is supported by both bearings. One of the bearings comprises an annular flange extending radially at the large end of the conical body and the other bearing has no flange. The screw holes and sliding holes are provided in the flange and in the interface of the bearing and of the hub for fastening the selected bearing to the hub for mounting the machine element over the shaft with screws to securely fasten the bearings on the shaft and the bore of the hub.
The Brazilian patent application BR 0900993-0 filed on Apr. 7, 2009, by Deere & Company and entitled “agricultural machine”, describes an agricultural machine 10 that includes a set of disk blade with a hub and a blade disk mounted on the hub. The rotor blade is deflectable by terrain forces in an area outside of the hub. A scraper assembly includes a mounting, a scraper blade and a hinge that interconnects the pivot to the scrapper blade on the mounting. The hinge has an axis of rotation that passes through a point generally in the bottom of the perimeter of the hub, or close to it, and generally coincident with the disk blade.
U.S. Pat. No. 6,257,678, filed on Sep. 23, 1999 by Meritor Heavy Vehicle Systems, LLC, and entitled “Vehicle hub having reduced lubricant cavity”, describes a vehicle hub comprising a body, usually cylindrical, which extends axially to form an inner seat of the roller, a seat of the outer bearing and between them a lubricant cavity. The hub is preferably chosen as an integral component from a ductile iron. A plurality of integral open ribs connects the body to a flange which extends radially. The ribs form an open space between the body and the ribs. The open structure of the ribs provides cooling for the bearings and lubricant, while reducing the weight without sacrificing the strength and rigidity of the hub. The cavity of the lubricant has a reduced diameter, which reduces the volume of lubricating medium required to fill the cavity and minimizes the centrifuge effect acting upon the medium.